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Population estimates provide a baseline to inform conservation and management decisions. In this paper, we present a novel method to derive non-breeding population estimates of waterbirds in Great Britain. We combined Wetland Bird Survey (WeBS) data with a detailed environmental stratification to calculate population estimates for widely dispersed waterbird species, populations of which tend to be relatively poorly monitored by WeBS and other established schemes. These stratification-based estimates were then compared with published estimates, most of which were derived using extrapolations based on WeBS information and a small number of intensive surveys. We discuss the limitations and merits of the stratification method, and conclude by suggesting the species for which future use of the approach would be most appropriate for derivation of population estimates. We also outline potential ways to improve the baseline information on abundance of widely dispersed non-breeding waterbirds in Great Britain. [ABSTRACT FROM AUTHOR]

The marine environment is increasingly pressured from human activities, such as offshore renewable energy developments. Offshore wind farms may pose direct risks to seabirds at protected breeding sites. However, changes in food availability may influence foraging behaviour and habitat use during the breeding season or between years. Consequently, seabird–wind farm interactions, and risks posed to populations, may vary over longer time scales, but this has seldom been quantified. We used GPS-telemetry to study the movements of 25 lesser black-backed gulls from the Alde–Ore Special Protection Area (SPA), UK between 2010 and 2012, while birds were associated with their breeding colony. Variation in movements away from the colony, offshore, and in operational, consented and proposed Offshore Wind Farm Areas (“OWFAs”) was investigated: (1) between years and (2) across the breeding season, addressing: (3) sex-specific, (4) individual and (5) diurnal/nocturnal differences. The extent of overlaps with OWFAs varied between years, being greatest in 2010 (7/10 birds showing connectivity; area overlap: 6.2 ± 7.1%; time budget overlap: 4.6 ± 6.2%) and least in 2012. Marine habitats close to the colony were used before breeding. Birds spent little time offshore as incubation commenced, but offshore usage again peaked during the early chick-rearing period, corresponding with use of OWFAs. Individuals differed in their seasonal interactions with OWFAs between years, and males used OWFAs significantly more than females later in the breeding season. This study demonstrates the importance of tracking animals over longer periods, without which impact assessments may incorrectly estimate the magnitude of risks posed to protected populations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Spaced learning induces persistence of spatial object recognition memory. • Persistence by spaced learning depends on the mechanism of memory expression. • Memory reconsolidation processes are not involved in the spaced learning effect. • Promotion of memory persistence involves a behavioral tagging process at retraining. • ERKs set the tag and GluA2-containing AMPA receptor is required at relearning. Spaced training, which involves long inter-trial intervals, has positive effects on memories. One of the main attributes of long-term memories (LTM) is persistence. Here, to identify the process that promotes LTM persistence by spaced learning, we used the spatial object recognition (SOR) task in rats. The protocol consisted of a first strong training session that induced LTM formation (tested 1 day after training), but not LTM persistence (tested 7 or 14 days after training); and a second weak training session that promoted memory persistence when applied 1 day, but not 7 days, after the first training. We propose that the promotion of memory persistence is based on the Behavioral Tagging (BT) mechanism operating when the memory trace is retrieved. BT involves the setting of a tag induced by learning which gives rise to input selectivity, and the use of plasticity-related proteins (PRPs) to establish the mnemonic trace. We postulate that retraining will mainly retag the sites initially activated by the original learning, where the PRPs needed for memory expression and/or induced by retrieval would be used to maintain a persistent mnemonic trace. Our results suggest that the mechanism of memory expression, but not those of memory reinforcement or reconsolidation, is necessary to promote memory persistence after retraining. The molecular mechanisms involve ERKs1/2 activity to set the SOR learning tag, and the availability of GluA2-containing AMPA receptor. In conclusion, both the synthesis of PRPs and the setting of learning tags are key processes triggered by retraining that allow SOR memory persistence. [ABSTRACT FROM AUTHOR]

Highlights: [•] For long-lived species, we show demographic indicators are more responsive to environmental pressures than those based on abundance. [•] Indicators can be corrected for the prevailing environmental conditions to provide a more accurate representation measure of anthropogenic impact. [•] Seabird breeding failure rates in the North Sea are linked to fisheries pressure, with those species most sensitive to fisheries experiencing the greatest increases in breeding failure. [ABSTRACT FROM AUTHOR]